Making noise and being aware are the best deterrents. A subset of being aware is not to get between the bear and its food or young.
I read the same study about the firecrackers....makes sense to me; The noise never stops so Brother Bruin never has a chance to indulge any latent curiosity and just defaults to thinking it's something bad.
Of course, then there are those times (such as when hunting them) that all bears are clairvoyant and stay away because they sense your intentions, even if one is quiet! :)